Microelectronic assemblies include integrated circuit components attached to substrates. Electrical interconnections are formed that allow communication between the integrated circuit component and the substrate for sending and receiving signals for processing. One type of a microelectronic assembly is a "smart card" assembly.
"Smart card" assemblies are credit-card-sized assemblies that include an integrated circuit component attached to a substrate. The integrated circuit component contains information, such as access privileges, account balances, and security information. Smart card assemblies typically include a plurality of electrical contacts on the surface of the smart card that permit electrical access to information stored in the integrated circuit component. The integrated circuit component is attached to the electrical contacts.
Contactless cards have been developed to allow utilization of the card without having to make physical contact with a mechanical reader head, thereby making the contactless cards faster to use and their functionality more transparent to the user. An antenna is typically disposed within the card to receive a signal transmitted from a base unit and to transmit a signal back to the base unit. In a contactless card, the integrated circuit component is typically embedded in the substrate, and is not attached to metal contacts on the surface of the card. In this manner, the position of the integrated circuit component is not based upon a need to be attached to metal contacts exposed at the surface of the card.
It is desired to form a microelectronic assembly that includes the functionality of both the contact card and the contactless card. Such dual interface "smart cards" include both contact pads on the surface of the card and contactless capabilities.
It has been difficult to achieve acceptable results with dual interface "smart cards". The process of connecting the embedded antenna to the integrated circuit component that has been attached to the external contacts has been difficult to achieve reliably. One proposed solution has been to include two integrated circuit components within each "smart card", one for the contact function and one for the contactless function. However, this approach leads to a more expensive smart card and a more complicated manufacturing process.
Therefore, a need exists for a microelectronic assembly that is able to be manufactured in an inexpensive, reliable way that incorporates the functions of both contact and contactless cards without the need for multiple integrated circuit components.